Changes of NGFI-B subcellular location in cardiomyocytes of stressed rats and its biological effects / 中国应用生理学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the changes of expression and subcellular location of nuclear growth-induced protein-B(NGFI-B) in cardiomyocytes of stressed rats and its biological effect and to provide scientific evidences for exploring the mechanism underlying myocardium injury induced by stress.</p><p><b>METHODS</b>The cell model of stress-induced cardiomyocyte injury were established. Western blot method and confocal microscopy method were used to investigate the subcellular location of NGFI-B in cardiomyocytes under stress. The flow-cytometry was selected to detect the apoptotic rate in cardiomyocytes in vitro. Western blot method was used to determine the content of cytochrome C protein in mitochondria and cytoplasm respectively.</p><p><b>RESULTS</b>Stress induced the increase of NGFI-B content in the mitochondria of cardiomyocytes and the translocation of NGFI-B from the nucleus to the mitochondria. The translocation of NGFI-B promoted the release of cytochrome C from the mitochondria and the cardiomyocyte apoptosis. Treatment of stressed cardiomyocytes with leptomycin B, a non-specific blocker of nuclear export, resulted in nuclear retention of NGFI-B and abrogated its ability to induce the release of cytochrome C from the mitochondria.</p><p><b>CONCLUSION</b>Stress could induce NGFI-B translocation from the nucleus to the mitochondria in cardiomyocytes, which activated the mitochondrial pathway of cell apoptosis.</p>